<!doctype html> 
<html> 
<head> 
    <meta charset="utf-8"> 
    <title></title> 
</head>
<body>
<script type="text/javascript">
	
	var arr = ['leo','18'];
	arr.unshift(1); //数组开头添加一个1
	alert(arr)
</script>
</body>
</html>